This invention relates to ultraviolet curing ovens for curing ultraviolet curable inks on cylindrical objects, and represents an improvement over the apparatus for curing of inks disclosed in the E. J. Whelan U.S. Pat. No. Re. 29,590 issued Mar. 21, 1978 and entitled "Apparatus For Radiation-Curing of Coating on Multi-Sided Object" and the S. Silverman U.S. Pat. No. 4,220,865 issued Sept. 2, 1980 and entitled "Ultraviolet Curing Oven With Rotatable Lamp Assembly".
In curing apparatus of the type disclosed in the aforesaid U.S. Pat. Nos. Re. 29,590 and 4,220,865 cylindrical objects having radiation curable decorations or coatings thereon are rotated as they move past one or more curing lamps in order to subject the entire outer surface of the object to more or less equal amounts of curing radiation. To positively control rotation of the objects, the inner surface thereof was engaged by a plurality of fingers or brush-like elements that were mounted on rotatable pins carried by a conveyor chain that traversed a closed-loop path. With that type of arrangement, it was necessary to provide means for positively rotating the pins and the means for loading and unloading objects on the pins was necessarily more complicated than loading of objects on pins that do not have fingers or brush-like elements that are closely fitted to the interior of the cylindrical object.
Further, the apparatus disclosed in the aforesaid U.S. Pat. Nos. Re. 29,590 and 4,220,865 required reflectors to be associated with the curing lamps in order to focus radiation toward the path traversed by the objects bearing the radiation curable material. The reflectors lost their effectiveness unless cleaned regularly and they had to be cooled in order to prevent warping which would inpair focusing properties thereof.